1. Field of the Invention
This invention relates to oral tetracycline-class antibiotic dosage forms, and in some embodiments, to controlled-release oral dosage forms of minocycline and methods of using them to treat acne.
2. Background
Acne affects large patient populations, and is a common inflammatory skin disorder which usually localizes in sebaceous areas of the body including on the face, back and chest. Fortunately, the disease usually disappears, and in the interval of months or years between onset and resolution, therapy, although not curative, can satisfactorily suppress the disease in the majority of patients.
Oral tetracycline-class antibiotics are frequently used in the treatment of acne. Tetracycline-class antibiotics are known to have some side effects. These side effects include vestibular symptoms such as vertigo, dizziness or blurred vision. These effects are sometimes disabling. See, Gould & Brookler, Arch. Otolarang. Vol. 96, p. 291 (1972); Williams et al., Lancet, Sep. 28, 1974, p. 144-45; Fanning & Gump, Arch. Intern. Med., Vol. 136, pp. 761-62 (1976). Headache and general malaise, along with gastro-intestinal symptoms such as the diarrhea, nausea, gas, or cramps may also occur. Dry nose and dry mouth are also occasionally encountered.
One of the oral tetracycline-class antibiotics used in the treatment of acne is minocycline hydrochloride. Oral dosage forms of minocycline hydrochloride are available commercially under various trade names. The Approved Drug Products with Therapeutic Equivalence Evaluations (“Orange Book”) lists a number of oral dosage forms of minocycline hydrochloride that are AB-rated to the MINOCIN® brand of minocycline hydrochloride. These commercial products are immediate-release oral dosage forms of minocycline hydrochloride that have been determined by the Food and Drug Administration (FDA) to be therapeutically equivalent to the MINOCIN® brand of minocycline hydrochloride on the basis of adequate in vivo and/or in vitro evidence supporting bioequivalence.
The dosing schedule used most frequently for treating acne using currently available immediate-release oral dosage forms is 100 mg of minocycline (free base equivalent) administered twice daily, see Leyden, J. Cutis 2006; 78 (suppl 4):4-5. However, some patients experience adverse effects with currently available immediate-release oral dosage forms, leading to reduced rates of patient compliance. See Stewart, M. et al., Cutis 2006; 78 (suppl 4):11-20. U.S. Pat. No. 5,908,838, which is hereby incorporated by reference, discloses slowly dissolving dosage forms of oral tetracycline-class antibiotics, including minocycline hydrochloride, that reduce the incidence or severity of vestibular side effects resulting from the treatment of acne.
Although the development of slowly dissolving forms of minocycline hydrochloride was a significant advance in the art, there remains a long-felt need for treatments that are effective in suppressing acne but associated with fewer adverse effects than those associated with the various immediate-release oral dosage forms of minocycline hydrochloride.